5000 meters max altitude, really?

[jokes_on_me]

According to cRIO specs the max altitude for the cRIO is 5000 meters. That's crap. So what you're telling me is that I couldn't operate this thing in a plane at normal altitudes if it's not pressurized. Is this true? Has anyone here tested any NI products at altitude? Thanks.

[aflojo]

Hi jdnelson,

It looks like there are a few resources on this being done/tested by some of NI's customers below:

http://www.ni.com/pdf/csma/us/NOAA_CompactRIO_Customer_Solution.pdf

But note, this product has not been certified for safe operation above 5,000m. Although specific tests might confirm system level functionality, National Instruments does NOT safety certify the product in question above 5,000m.

Hope this helps!

[Larry_Morgan]

One of the biggest drivers for the maximum altitude in many CompactRIO modules' rating is the safety isolation present. Many of these products are designed to IEC/UL/etc specifications for measurement equipment safety rating (CAT I, CAT II, etc). Those specifications dictate maximum altitude and/or a derating above the specified altitude. This is due largely in part to the effective dielectric strength of air decreasing with altitude. 

Would the equipment to which you are referring suddenly quit working above 5000m? Likely not. However its specifications would not be warranted and it would be outside its specifications for the listed isolation.

Hope this helps!

-Larry

[CFER_STS]

Could this also have to do with the effectiveness of passive convective cooling (heatsinks) in the thinner air?

[RizwanSaleem]

hi, is the test conducted for cRIO devices is also valid for sbrio-9651? 

[KeddyC]

Hi Rizwan,

Thanks for reaching out. The sbRIO-9651 is spec'd to 5000m of altitude as well, however the above statements apply to this device as well.